To produce outerwear apparel by using water vapor permeable plastics foils, the problem which needs to be addressed in many cases is that of providing an outerwear material which satisfies consumer esthetics with regard to optics and haptics and is efficiently bondable to the water vapor permeable plastics foil in question without being impaired in advantageous properties.
Grain leather and suede leather have attractive optics and haptics, but are generally very expensive and in many cases less than optimal in terms of breathability. Nubuck leather has pleasant haptics, but generally is sensitive and has poor physical fastnesses.
The present invention has for its object to process water vapor permeable plastics foils such that they retain their water vapor permeable properties yet have an appealing visual exterior and pleasant haptics. The present invention further has for its object to provide uses for thus processed water vapor permeable plastics foils.
We have found that this object is achieved by the multilayered composite materials defined at the beginning. They comprise as components:    (A) a water vapor permeable plastics foil,    (B) optionally at least one bonding layer, and    (C) a polyurethane layer with capillaries passing through the entire thickness of the polyurethane layer.
By water vapor permeable plastics foils (A), herein also referred to as foil (A) in brief, are herein meant sheetlike structures composed of synthetic polymer, which can have a thickness of 0.5 μm to 1 mm, preferably 1 μm to 0.5 mm and more preferably 5 μm to 0.05 mm. The term polymer herein also comprises copolymers.
By “water vapor permeable” herein is meant a material that has a water vapor permeability or water vapor transmission rate (WVTR) of more than 1 mg/cm2 h to German standard specification DIN 53333.
In an embodiment of the present invention, water vapor permeable plastics foils (A) comprise water vapor permeable plastics foils which are impermeable to water in the liquid state of aggregation. This “impermeable to water in the liquid state of aggregation” shall be determined at atmospheric pressure or not more than 2 atmospheres pressure.
Plastics herein are polyolefins and preferably fluorinated, more preferably perfluorinated polyolefins such as for example polytetrafluoroethylene and copolymers of tetrafluoroethylene with other fluorine-containing comonomers, in particular hexafluoropropylene.
Water vapor permeable plastics foils (A) of polyolefin, preferably of fluorinated polyolefin can be rendered water vapor permeable by mechanical expansion in particular. Water vapor permeable plastics foils (A) of polyolefin, preferably of fluorinated polyolefin can have pores having an average diameter in the range from 1 to 50 μm, in particular of about 10 μm.
In an embodiment of the present invention, foil (A) has an amorphous fraction of about 5% or more.
Examples of producing expanded foils (A) and their production are recited in U.S. Pat. No. 3,953,566.
In another embodiment of the present invention, foils (A) are foils of polyester, polyamides and polyurethanes, preferably chemically modified polyamides or polyurethanes and, in particular, chemical modified polyesters.
The chemically modified polyamides, chemically modified polyurethanes and chemically modified polyesters comprise in particular hydrophilic modified polyamides, polyurethanes and polyesters respectively, which have been modified through incorporation of one or more polyethers such as diethylene glycol, triethylene glycol, tetraethylene glycol or polyethylene glycol, for example, to be hydrophilic. They may also be referred to as polyether-amides, polyether-urethanes and polyether-polyesters, respectively.
The material of which foil (A) is composed differs from the material of which polyurethane layer (C) is composed.
Multilayered composite material of the present invention further comprises at least one polyurethane layer (C) with capillaries passing through the entire thickness of the polyurethane layer. Polyurethane layer (C) with capillaries passing through the entire thickness of the polyurethane layer is herein also referred to in brief as polyurethane layer (C).